Double Offset Butterfly Valve
The double offset butterfly valve incorporates two distinct offsets, both involving the displacement of its shaft from the centreline. The first offset positions the shaft away from the centreline of the disc seat and body seal, ensuring a continuous sealing surface throughout the valve's operation.
The second offset shifts the shaft from the pipe/bore centreline, facilitating the smooth lifting of the disc and seal away from the body seat. This results in a cam-like motion that efficiently separates the seat from the seal during operation. Notably, friction between the disc and seal is limited to the initial 10° of opening and the final 10° of closing.
Renowned for its high performance, the double offset butterfly valve is ideally suited for high-temperature and high-pressure applications, offering reliable on-off or throttling services.
Range Specifications:
·Sizes: 2" to 80" (DN50 to DN2000)
·Pressure Ratings: ASME CLASS 150 to 600 (PN16 to PN100)
·Temperature Range: -46°C to 200°C (-51°F to 400°F)
Construction Highlights:
·Material: Cast Steel
·Seating Options: Soft Seated (EPDM, NBR, PTFE, RPTFE)
·End Connections: Flanged, Wafer, Lug, Butt Welded (BW)
·Body Compositions: Monel, Inconel, Hastelloy, Incoloy, Duplex & Super Duplex Steels, Carbon Steel (including Low Temp), Low Alloy Steel, Stainless Steel, Titanium, etc.
Compliance & Standards:
·Design: MSS SP-67, API 609, EN 593, BS 5155, ISO 10631
·Flanged Ends: ASME B16.5
·Face-to-Face: ASME B16.10, EN 558, JIS B2002, MSS SP-72
·Mounting Pad: ISO 5211
·Pressure-Temperature: ASME B16.34
·Inspection & Testing: API 598, EN 12266, MSS SP-82, ISO 5208
·Fugitive Emission: ISO 15848, API 624, API 641
·Fire-safe: API 607, API 6FA, ISO 10497
Features:
·Bi-directional operation
·Bubble-tight shut-off capability
